prolong
v.
early 15c., back-formation from prolongation or else from Old French prolonguer, porloignier (13c.), from Late Latin prolongare "to prolong, extend," from Latin pro- "forth" (see pro-) + longus "long" (adj.); see long, adj.. Related: Prolonged; prolonging; prolongable.
〔李〕[pro-;long] v.延长； 拉长； 拖延 ←long (L longus)=long 长的